SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62ffbc14cdd3923ecc67f9acaca9614854df3324d9512efb5670780577c9a950' 
  AND token = 'zdAxwyI2ML1Gh64sDymJZh0eY+7BEcYFTnpPnS20JjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}